1. Field of the Invention
The present invention relates to lesion localization needles and devices, for use in localizing or marking non-palpable lesions and tumors within the body, and more particularly, the present invention relates to a needle assembly which includes a wire marker having a helically wound wire tip for rotatingly anchoring a marker to a lesion within a human breast.
Localization or marking of lesions within the body, such as non-palpable lesions discovered within the body, and devices such as needles and wires for marking these lesions, are well known in the art. The devices generally comprise a hypodermic needle or cannula which is inserted into the body under local anesthesia to a position adjacent and in contact with the lesion. The wire marker is then passed through the cannula and is anchored into the lesion so that the lesion is marked for subsequent surgical procedures such as excision or biopsy. After marking the lesion with the wire marker, the cannula is usually removed from the body, leaving the wire in place and extending from the body. However, these markers tend to dislodge and migrate during transport of the patient for the surgical biopsy procedure.
Increasingly, ultrasonic imaging is being used as a preferred ancillary or adjunctive imaging method to evaluate breast masses which may be associated with positive or negative mammographic findings. Currently available localization and marking devices image poorly, if at all, ultrasonically, making it difficult to accurately pinpoint the tip of the localization wire with respect to the lesion. Consequently, a subsequent surgical biopsy procedure may result in an inaccurate incision causing unnecessary tissue damage, and may necessitate a second surgical procedure to properly biopsy the lesion, causing the patient unnecessary pain, suffering, and expense.
2. Discussion of the Prior Art
In the prior art, several types of lesion localization devices and lesion markers are disclosed. Currently, the method of detecting and performing a biopsy on a non-palpable occult lesion within the body, such as non-palpable breast lesions, has been to radiologically or ultrasonically locate the lesion and to mark the lesion using a localization needle assembly, prior to a biopsy procedure. These needle assemblies generally comprise a hypodermic needle or cannula which is inserted into the body to an area adjacent to and in contact with the lesion. A marking wire is then inserted through the cannula into the lesion and anchored in place so that the cannula may be removed.
Ultrasonic imaging is increasingly being used as the preferred method of detection and evaluation of lesions and masses within the body due to its accuracy, and in view of the fact that the patient is not exposed to potentially harmful radiation for extended periods of time. The prior art marking devices generally image very poorly ultrasonically, as the tip of the previous marker shows up as a small, hard to locate dot or spot on the viewing screen. Depth perception is very limited, and consequently, accurate, reliable placement of the previous marking device is not guaranteed.
Nicholson, et al., U.S. Pat. No 4,616,656, discloses a probe wire and sheath assembly in which the wire has a J-type memory hook for marking lesions. The wire probe has a soft flexibility so that when it is enclosed within the sheath it has a straight configuration. The sheath, or needle, is inserted into the body, for instance into the breast of a female patient, and positioned proximate to a lesion. The wire probe is then pushed further into the lesion so that the memory hook is reformed and anchors itself within the lesion. The sheath is then removed leaving the hook embedded in the lesion as a marker.
A similar device is disclosed in Hawkins, Jr , U.S. Pat. No. 4,230,123. Hawkins, Jr. discloses a needle sheath assembly which consists of a small gauge needle in which a stylus or wire is positioned within a cannula. A shorter outer sheath is slidably located over the cannula which is removable after insertion of the needle into the patient's body. The wire has a J-type hook which is passed through the cannula to stabilize the tip of the cannula during biopsy.
Nicholson, et al. and Hawkins, Jr. are subject to several disadvantages which effect the accuracy and performance of the device. Devices such as those disclosed in these references image very poorly and are inconsistently visualized ultrasonically, and consequently may not be accurately placed. Furthermore, in procedures involving lesions of the breast, the breast is compressed during the mammographic localization procedure so that after the needle is in place and compression discontinued, the needle marker may inadvertently dislodge or migrate to a different position than that set during the localization procedure. The needle may also deflect away from the lesion, or if the strength and resiliency of the wire is less than that required to penetrate the lesion, the hook may not reform, allowing the marker to migrate or dislodge. This can result in damaging the tissues of the breast, as well as an inaccurate surgical incision during the biopsy procedure, usually requiring a second surgical procedure to properly biopsy the lesion, causing the patient unnecessary pain, suffering and expense. Devices of this type also generally require that the breast be stabilized during transport of the patient from the radiology section of a hospital to the surgical section for the biopsy procedure in order to prevent dislodgement of the marker.
Simon, U.S. Pat. No. 4,790,329, discloses a biopsy localization device having a sheath or cannula through which a barbed rod passes. The cannula is provided with an open side port through which the barb extends upon positioning within a lesion. In use, the barb is compressed within the lumen of the cannula and the pointed end of the rod extends from the cannula. As the device penetrates the patient's body, and into a lesion, the rod is rotated 180.degree. so that the end of the barb may pass through the open side port of the cannula. The rod is then drawn back so that barb and cannula anchor into the lesion to prevent removal. While the device is relocatable, such as by drawing back the cannula to enclose the barbed rod after anchoring, it is apparent that some tissue damage will result due to the barb puncturing the tissue once it is anchored. In addition, the cannula remains in place while the lesion is marked by the barb, which results in excessive weight applied to the tissue. The entire device must be stabilized in order to prevent tearing of tissue and dislodgement of the marker. As related to breast lesions, as discussed above, compression of the breast during the procedure provides accurate anchoring of the barb; however, during transport of the patient, the additional weight of the cannula as well as the barbed rod will require stabilization of the breast to prevent migration and dislodgement of the device. A similar device, facing the same disadvantages, is disclosed in Hawkins, et al , U.S. Pat. No. 4,799,495.
An additional type of prior art lesion localization and biopsy device is commonly referred to as the "Nordenstrom Screw Diagnostic Instrument", which was developed by Bjorn Nordenstrom (Radiology, November 1975, Volume 117, Page 474). The Nordenstrom screw is generally a biopsy device and not a lesion localization and marking device. A cannula is provided which is inserted into the body, having a screw-tipped rod within the lumen of the cannula. When the cannula is positioned proximate a lesion, the rod is rotated to screw the tip into the lesion. The screw tip is integral with the rod itself, and is a finely machined device in which the screw threads define grooves which taper to the tip of the device. After the screw tip is rotated into the lesion, the cannula is then rotated in an opposite direction using slight forward pressure to a position over the screw threads. Tissue from the lesion is captured in the grooves of the screw tip and the entire device is withdrawn so that the tissue may be examined. The Nordenstrom screw device, as stated above, is not a marking device, but instead allows the physician to immediately biopsy the lesion in question.
An additional marking device using a screw tip is disclosed in Hawkins, et al., U.S. Pat. No. 4,799,495. In this device, the cannula may be provided with a tapering screw tip to anchor the cannula in the tissue while the needle marker penetrates the lesion. The cannula and wire are used to mark the lesion, and Hawkins et al. also discloses the use of the cannula alone for marking the lesion. Furthermore, Hawkins et al. discusses a helical screw needle marker, similar to the Nordenstrom screw device, which may be inserted through the cannula to mark the lesion. However, the tapering screw tip of Hawkins et al is a finely machined device which is quite expensive to manufacture, and which also is subject to the disadvantage that the tapered end may result in the loosening or "backing off" of the screw tip which will dislodge the marker during transport of the patient, or upon discontinuation of compression of the breast during the marking procedure. Furthermore, the precise machining of the tip of this device, and in particular a hollow screw-tipped cannula, would be a difficult and very expensive procedure from a manufacturing standpoint, and would necessitate that the device be reusable due to these cost considerations. In view of this, and in light of current health risks and concerns for patient safety as related to blood products and invasive surgical procedures, sterilization procedures would be required prior to and after each use, thereby making the procedure more elaborate and expensive then normally necessary.
The novel, disposable lesion localization and marking device of the present invention obviates the problems associated with the prior art lesion localization devices by providing an inexpensive, simple to manufacture lesion marking device having a helically wound marking wire attached to a wire shaft which passes through a hypodermic needle comprising a cannula. The helically wound marking wire extends concentrically outward from the shaft and maintains a substantially uniform diameter so that once the wire is rotated or screwed into a lesion, it remains anchored in the tissue without the possibility of backing off and dislodging.
In a preferred embodiment, a second helically wound wire is provided on the shaft remote from the first helically wound wire at the tip which, in conjunction with a wire guide provided on a gripping knob of the cannula, assists in the forward advancement of the shaft so that excessive forward pressure is not required, and the second helix also acts as a depth guide to provide an accurate indication of the depth to which the first helix is embedded in a lesion. The helically wound wires are secured to the shaft by means such as soldering, or may be wound as part of the shaft itself, so that the entire device is simple to manufacture and relatively inexpensive, thereby making the device disposable following the biopsy procedure.